©Journal of Sports Science and Medicine (2003) 2, 110-116 http://www.jssm.org

Research article

TREADMILL AND CYCLE ERGOMETER TESTS ARE

INTERCHANGEABLE TO MONITOR TRIATHLETES ANNUAL

TRAINING

Fabien A. Basset * and Marcel R. Boulay

Division de Kinésiologie, Département de Médecine Sociale et Préventive, Faculté de Médecine, Université Laval, Ste-Foy (Québec), Canada

Received: 05 May 2003 / Accepted: 07 August 2003 / Published (online): 01 September 2003

ABSTRACT The purpose of this study was to verify the use of a single test to obtain annual training guidelines applicable to multiple modes of training. Eight triathletes (4 females, 4 males) were tested 3 times during their training year (Phase I; Phase II; Phase III) on a treadmill and cycle ergometer. Cardio-respiratory variables were calculated at standardized percentages of maximal uptake (VO2max; 50-100%). VO2max differences between tests reached 6% in every testing session (p £ 0.01). VO2max was stable for both tests throughout the season. The ANOVA (3 phases x 2 tests x 6 intensities) demonstrated that there was a significant difference for heart rate (HRs ; p £ 0.05) between tests in Phase I only. However, the nonparametric sign test did not show any significant differences in any phase. These results demonstrated that triathletes could use the relationship between HR and % VO2max collected during a treadmill or a cycle ergometer test to obtain interchangeable reference HRs for monitoring their and training bouts in high volume and/or high intensity phases of their training year.

KEY WORDS: Performance test, triathlete, VO2max, monitoring of training, heart rate.

INTRODUCTION adaptations, induced by different modes of training require that specific tests should be used in order to Sport training induce physiological monitor training effects. Therefore, precise adaptations that enhance athletic performance monitoring of training adaptations in triathletes (Mujika and Padilla, 2000a; Mujika and Padilla, should theoretically involve testing in the three 2000b). To provoke adequate physiological modes of training. On the other hand, it has been adaptations, specific task have to be done under reported in a previous study (Basset and Boulay, specific conditions, where the task is characterized 2000) that the heart rate (HR) differences between a as a set of particular physical and psychological cycle ergometer and a running test, in triathletes, stressors (i.e., the principal of specificity) (Viru and cyclists and runners were smaller than the habitual Viru, 1993). Triathletes are in a particular position intra-individual variations observed while carrying when considering training specificity because they out prolonged training activities. This latter results evidently have to devote a portion of their training to confirmed an acute HR adaptation to different , biking and running while other athletes modes of testing. What about long-term HR have generally a single mode of training. Triathletes adaptation? face additional difficulties because specific Triathletes and their coaches have been physiological adaptations, particularly peripheral interested in establishing the optimal work intensity Laboratory tests and training monitoring 111

with accurate indicators to determine the overall Maximal oxygen uptake test (VO2max) density of training (composite of volume and Subjects underwent continuous, incremental tests to intensity of training (Boulay, 1995)) programs. Even volitional exhaustion on a treadmill and cycle though VO2max is related to endurance performance, ergometer. Tests were terminated when subjects some day-to-day variations convey restriction on the could no longer keep pace with treadmill or could no use of this variable alone (Arts and Kuipers, 1994). longer keep rpm ³ 60. These two maximal tests were Thus, to prescribe intensities coaches need carried out in random order with a minimal interval a criterion that reflects the specific physiological of two days and a maximal interval of seven days responses of their athletes (Basset and Boulay, between tests. Test protocols were designed to yield 2000). approximate similar test duration. The running test Heart rate and VO2 have been shown to be was conducted on a motor-driven treadmill (Quinton linearly related in cycling as well as in running Instruments, Seattle WA). After a 5 min warm-up at (Coast and Welch, 1985; Ricci and Leger, 1983; a speed of 3.5 km.h-1, the starting speed was set at Swain and Leutholtz, 1997; Swain et al., 1998; Van 5.5 km.h-1 and 5% grade, and was increased every Handel et al., 1988). Thus, HR has been frequently two min by 1.1 km.h-1 until 13.2 km.h-1 after which taken as the variable of choice to monitor work the grade was raised by 3% every two min until intensity in athletes using running and/or cycling in exhaustion. The ergocycle test was performed on an their training (Pichot et al., 2000). Therefore, HR electromagnetically braked cycle ergometer (Warren has been proposed for prescribing exercises for E. Collins, Braintree, MA). Subjects were asked to training bouts of short duration (15-30 min) choose a familiar and comfortable pedalling rate (Weltman et al., 1990). Heart rate has been shown to greater than 60 rpm and to maintain it through the be a more stable variable during prolonged exercise test. It should be noted that the mean value of (90 min) than other physiological variables, such as pedalling rate was about 90 rpm for the entire group. pulmonary ventilation (VE), work rate (W), blood The test was initiated at an initial power output of lactate and expired carbon dioxide (VCO2) and thus 100 W after a 4 min warm-up period at 100 W. has been proposed for the same purpose in longer Increments of 25 W were made every min until 200 training activities (Boulay et al., 1997). Establishing W was reached then afterwards at every 2 min until training intensities with HR gathered during exhaustion. common laboratory exercise tests thus seem to be an efficient approach for monitoring exercise intensity Physiological measurements and density of training (Boulay, 1995). During the tests, VO2, VE and respiratory exchange Based on our previous study (Basset and ratio (RER) were continuously recorded (average of Boulay, 2000), demonstrating a strong HR 30 s) with an automated open circuit gas analysis relationship between cycle ergometer and treadmill system using O2 and CO2 analyzers (Model S-3A tests, we hypothesize that this latter result would and Anarad AR-400, Ametek, Pittsburgh, PA), and a also be found all through triathletes annual training turbine driven digital spirometer (Model S-430, (i.e., long-term adaptation). Therefore, the aim of the Vacumetrics/Vacumed Ldt., Ventura, CA) with a present study was to verify the feasibility of using a 5.3L mixing chamber. Heart rate was recorded by single laboratory test to obtain training guidelines electrocardiography in the CM6 position (Model applicable to multiple modes of training. M200, Burdick Corp., Milton, WI). Criteria for reaching VO2max were plateauing in spite of an METHODS increase in speed or work rate and a respiratory exchange ratio value greater than 1.1. All subjects at Subjects least showed one of the above mentioned criteria. Eight triathletes (4 females and 4 males; age 22 ± 2 Heart rate at exhaustion was taken as maximal heart years; body mass 60.7±10.0; height 1.70 ± 0.08 m), rate (HRmax). gave their written informed consent (in compliance with Université Laval’s Ethics Committee Training program regulations) to participate in this study. All subjects Subjects maintained their habitual training and were active athletes and had been competing at the competition regimen through the year. During Phase provincial and national levels for periods ranging I, corresponding to general preparatory training (13 from 2 to 12 (5 ± 4) years. Tests were performed in weeks), training sessions focused on light aerobic three different training phases. First in fall during the workouts performed by swimming, running and general preparatory training phase (Phase I), then in cycling plus two weight training sessions per week. winter during the specific preparatory training phase In Phase II, corresponding to specific preparatory (Phase II) and finally in summer at the beginning of training (13 weeks), while weight training sessions the competitive phase (Phase III). were maintained, emphasis was centered on 112 Basset and Boulay

Table 1. Training volume per week in running cycling and swimming. Data are mean ± (SD). Training volume Phase I Phase II Phase III All year Volume Duration Volume Duration Volume Duration Volume Duration (km) (h) (km) (h) (km) (h) (km) (h) Running 42.4 3.31 55.9 4.39 53.9 4.29 50.8 4.13 (7.2) (0.36) (5.6) (0.27) (6.9) (0.34) (8.8) (0.43) Cycling 107.3 3.34 237.7 7.55 438.5 14.36 265.5 8.51 (20.3) (0.40) (303.8) (10.07) (132.3) (4.24) (231.7) (7.43) Swimming 16.2 4.37 17.4 4.57 18.6 5.18 17.4 4.58 (5.4) (1.33) (9.2) (2.38) (4.2) (1.13) (6.5) (1.51)

swimming and running workout sessions whereas sample of observations. Significant F-ratios were cycling volume increased two fold mainly due to a followed by post-hoc comparison using Tukey HSD training camp. In Phase III, corresponding to pre- test procedure. For all statistical tests, a p £ 0.05 was competition season (14 weeks), the cycling volume considered significant. All values are expressed as increased again while swimming and running means ± (SD). volumes were maintained. Mean overall volumes -1 -1 (km·wk and h·wk ) for each training mode and RESULTS each phase are presented in Table 1.

Statistical analysis Table 2 presents maximal physiological responses to Firstly, a two-way (3 phases x 2 tests) analysis of cycle ergometer and treadmill tests during the variance was performed to look at phase and mode training year. Values of HRmax were significantly of testing effects on test duration, HRmax, maximal higher on treadmill than cycle ergometer (p £ 0.01) pulmonary ventilation (VEmax), and VO2max relative for each testing session. HR differences between to body mass. Secondly, physiological variables tests varied from 3 beats· min-1 during Phase I to 4 during the incremental tests were interpolated, using beats· min-1 during Phase III. Test durations were not a resampling function (MatLab 6.1 Software, significantly different between phases but tended to MatWorks, Boston, MA), for six relative intensities last longer in Phase III. (from 50% to 100% of VO2max) to compensate for The subjects had significantly higher relative different absolute values between individuals and VO2max on treadmill (~6%) than cycle ergometer (p between tests. The cardio-respiratory data were £ 0.01) for each testing session. analyzed using a three-way (3 phases x 2 tests x 6 Figure 1 shows mean HR plotted against fixed intensities) analysis of variance with repeated percentages of VO2max (50-100%). Significant measures on three factors. Based on a previous study differences (p £ 0.05) were found between tests on of triathletes (Basset and Boulay, 2000), a priori mean submaximal HR. A priori contrast analysis contrast statements were designed to test: (a) the indicated that differences were restricted to HRs effects of training phases and (b) the effects of mode observed from 70% of VO2max to VO2max in Phase I of testing. In addition, to assess intra-individual HR only. No HR differences were found between phases differences between tests the non-parametric Sign on each mode of testing. test was computed. This test was used because the The nonparametric sign test on HR did not differences were treated as a single sample, and the show differences between cycle ergometer and random assignment of treatments to units within treadmill at any percentage of VO2max through the each pair justifies the assumption of a random season.

Table 2. Maximal physiological responses to cycle ergometer and treadmill tests during a triathlon season. Cycle ergometer Treadmill

Period Duration HRmax VEmax VO 2 max Duration HRmax VEmax VO 2 max (min) (min) Phase I 15.0 (5.2) 193 (8)* 140.5 (34.0) 60.9 (6.7)* 17.8 (2.1) 196 (7.3) 136.6 (24.7) 64.8 (5.8) Phase II 15.7 (5.6) 192 (8)* 144.2 (36.6) 61.9 (6.4)* 18.6 (1.9) 195 (8.1) 136.5 (25.4) 66.1 (6.9) Phase III 16.0 (5.7) 191 (8)* 146.9 (25.8) 62.8 (7.2)* 19.0 (1.8) 195 (8.4) 143.2 (25.4) 67.1 (5.9) -1 -1 Abbreviations: HRmax= Maximal heart rate (beat·min ), VEmax= Maximal pulmonary ventilation (l·min ), -1 -1 VO2 max = Maximal oxygen uptake (ml·min ·kg ).Data are mean ± (SD). * Mode effect (p £ 0.05). Laboratory tests and training monitoring 113

Figure 1. Mean heart rate plotted against fixed percentages of VO2max for the cycle ergometer (£) and treadmill (q) tests performed in Phase I (left), Phase II (middle) and Phase III (right). * p £ 0.05, ** p £ 0.01.

DISCUSSION treadmill running. Moreover, Verstappen et al. (1982) postulated that a submaximal stimulus of The purposes of the present study were firstly, to neurogenic origin, due to the smaller muscle mass look at the triathlete long-term HR adaptation on used during cycle ergometer produced lower HRmax. ergometer and treadmill tests; secondly, to verify the The maximal HR differences between tests reached -1 use of a single test to obtain yearly training about 4 beats· min and were in the range of the guidelines applicable to multiple modes of training variations habitually observed during training in triathletes. The main finding of the study sessions. demonstrates that HR at different relative intensities Over the training year, the subjects running did not show major differences between running and VO2max values were significantly higher than their cycle ergometer tests during most parts of the cycling VO2max. Running and cycling VO2max training year. Our investigation brings new increased by about 3% during the season. Mean information with regard to the monitoring of cycling VO2max represented about 94% of running multiple modes of exercise in triathlon. Thus, the VO2max for each testing session. These proportions results indicate that triathletes could use a single are similar to those seen in runners or untrained mode of testing to obtain their training HR in subjects (~90%) but higher than those observed in running and cycling throughout the year. highly trained cyclists (~100%) (McArdle and At maximal work rate, significant differences Magel, 1970; Pechar et al., 1974). Individuals were observed in HRmax between tests with higher differences between tests varied from 0 % to 17 %. values on the treadmill. These results are in Kohrt et al. (1989) found similar pattern in a agreement with some previous reports (Basset and longitudinal study of trained triathletes and Boulay, 2000; Martinez et al., 1993; McArdle and suggested that greater differences between running Magel, 1970; Medelli et al., 1993; Schneider and and cycling of well-trained triathletes arose from Pollack, 1991; Zhou et al., 1997) but different from muscle mass adaptations of the leg extensors. Thus, others which reported no significant differences triathletes must find the best combination of these (Hermansen and Saltin, 1969; Moreira-Da- Costa et two somewhat opposing modes of training to al., 1989; Schneider et al., 1990). Fernhall and Kohrt optimize performance in both events. It is interesting (1990) showed that responses in local muscles to note that running and cycling VO2max did not produced an effect on central circulation by having change over the seasons probably because of smaller muscle mass involvement and leg blood insufficient increases in training volume and/or flow during cycle ergometry compared with intensity to induce cardio-respiratory adaptations or 114 Basset and Boulay

because subjects had reached their potential in this random sample in the true sense of the definition. component. Similar results over yearly phases of Most studies deal with a systematic sample, not a training have been reported by others (Barbeau et probability sample. In addition, random factors are al., 1993; Bunc and Heller, 1989; Perez, 1981). It frequently introduced into experiments that justify has been suggested that the maintenance training parametric statistical inferences. In fact, those program performed by athletes during the statistical procedures are too sensitive facing regenerative phase is sufficient to maintain their biological variations and produce statistical VO2max in spite of a fairly reduced volume (Barbeau significant differences which in practice are often of et al., 1993). This tends to indicate that, in well- little importance. To eliminate the probability of a trained subjects, maximal trainability appears to be type II error, the proper statistical procedure to use is maintained with a relatively small volume of the Sign test. With this test, no statistical difference training provided that training intensity is adequate was observed on the paired comparisons between (Hickson et al., 1985; Koutedakis, 1995). cycle ergometer and treadmill tests throughout the Due to the restricted number of subjects, season. This means that HR adaptation during the analysis was computed with gender factor blocked. training year followed similar patterns in both modes Nevertheless, descriptive statistics showed that men of testing. This conclusion ensured athletes and VO2max had reached higher values than women on coaches that the use of HR at relative percentage of both tests through the season. Men values ranged VO2max to monitor training sessions is valid. This from 68.5±1.4 to 71.6±2.1 ml· min-1· kg-1 and from confirmed the results of a previous study (Basset and 65.7±1.9 to 68.3±2.1, while women values ranged Boulay, 2000) which demonstrated that the HR from 61.2±2.9 to 62.7±1.6 ml·min-1·kg-1 and from generated on cycle ergometer or treadmill could be 56.1±2.7 to 57.3±2.5 for treadmill and cycle used interchangeably to monitor intensities with ergometer, respectively. Even though the subjects either mode of exercise in samples of runners, displayed some physiological differences owing to a cyclists and triathletes. gender effect, they represented a good cluster of Mean training volume (Table 2) for cycling competitive athletes. and running were similar to those reported in A priori contrast statements revealed that previous studies (Hickson et al., 1985; Kohrt et al., when expressed against percentages of VO2max, HRs 1989; Schneider et al., 1990). Mean weekly volume during Phase I were significantly different between of cycle training increased the most during the tests from 70% of VO2max up to maximal oxygen training year (+ 76% from Phase I to Phase III) uptake while no difference was observed in Phase II whereas mean weekly volume of running increased and Phase III. These results confirm that the training the least throughout the year (+ 24%). Mean period plays a major role in cardio-respiratory swimming volume was slightly higher in this study fitness. Thus, when athletes were tested in their than those reported by others (Kohrt et al., 1987; competitive phase no HR differences were observed Kohrt et al., 1989; Schneider et al., 1990), reaching between cycle ergometer and treadmill tests when 18.6 km· wk-1 during Phase III and was the most work intensities were expressed in percentage of stable training variable through the season with a VO2max (Martinez et al., 1993; McArdle and Magel, small 13% increase from Phase I to Phase III. When 1970). On the other hand, Hermansen and Saltin expressed as duration, the difference between modes (1969) reported a different pattern as their subjects of training was the lowest during Phase I. Mean achieved higher HRs on cycle ergometer than weekly duration of training between cycle and run treadmill at the same metabolic rates expressed as % was almost the same. While, weekly volume of of maximal power. They assumed that a position running training progressed smoothly through the effect was present with a reduced venous return and season to reach a maximum during Phase II, a lower stroke volume in the sitting position. swimming and cycling training volumes However, the trend for higher HRs on cycle demonstrated larger variations due to training camps ergometer was reduced with training as trained during Phase II. subjects demonstrated smaller differences (4 The tests used in the present study were -1 -1 beats· min ) than untrained subjects (11 beats·min ). designed to generate comparable VO2 at each stage In the present study, the decrease HRs at and to give comparable VO2 increments between submaximal work load appeared in the running test stages as reported in the previous study from our only. This probably reflects the fact that the training laboratory (Basset and Boulay, 2000). Moreover, to program showed a greater emphasis on running than ensure that test results would be comparable, results cycling in the first two phases of the training year were reported against fixed percentages of VO2max. and that cycling volume was then not optimal. The expression of work intensity in a relative form In many experimental studies, particularly in (% of VO2max) has definitive merits because it allows exercise sciences, it is almost impossible to obtain a groups with very different characteristics to be Laboratory tests and training monitoring 115

directly compared. This procedure ensured that the Hermansen, L. and Saltin, B. (1969) Oxygen uptake results of both cycling and running were not only during maximal treadmill and bicycle exercise. comparable but also applicable to field situations in Journal of Applied Physiology 26: 31-37. mimicking what athletes do in the field because Hickson, R. C., Foster, C., Pollock, M. L., Galassi, T. M. habitually they do not adhere to the same and Rich, S. (1985) Reduced training intensities standardized work protocols in different exercise and loss of aerobic power, endurance, and cardiac growth. Journal of Applied Physiology 58: 492- modes (Basset and Boulay, 2000). 499. Kohrt, W. M., Morgan, D. W., Bates, B. and Skinner, J. CONCLUSION (1987) Physiological responses of triathletes to maximal swimming, cycling, and running. In conclusion, the results of the present study Medicine and Science in Sports and Exercise 19: indicated that athletes and coaches could use a single 51-55. mode of testing to obtain their training guidelines in Kohrt, W. M., O'Connor, J. S. and Skinner, J. S. (1989) running and cycling. The relationship between HR Longitudinal assessment of responses by triathletes and oxygen consumption expressed as percentages to swimming, cycling, and running. Medicine and Science in Sports and Exercise 21: 569-575. of VO2max, gathered throughout the season during Koutedakis, Y. (1995) Seasonal variation in fitness cycle ergometer and treadmill tests, could be parameters in competitive athletes. Sports interchangeably used, in these athletes, to monitor Medicine 19: 373-392. the intensity of training sessions either in running or Martinez, M. L., Modrego, A., Ibanez Santos, J., Grijalba, in cycling activities. However, it remains to be A., Santesteban, M. D. and Gorostiaga, E. M. determined if the same conclusion could be stated (1993) Physiological comparison of roller skating, with swimming training. treadmill running and ergometer cycling. International Journal of Sports Medicine 14: 72- 77. REFERENCES McArdle, W. D. and Magel, J. R. (1970) Physical work capacity and maximum oxygen uptake in treadmill Arts, F. J. P. and Kuipers, H. (1994) The relation between and bicycle exercise. Medicine and Science in power output, oxygen uptake and heart rate in male Sports and Exercise 2: 118-123. athletes. International Journal of Sports Medicine Medelli, J., Maingourd, Y., Bouferrache, B., Bach, V., 15: 228-231. Freville, M. and Libert, J. P. (1993) Maximal Barbeau, P., Serresse, O. and Boulay, M. R. (1993) Using oxygen uptake and aerobic-anaerobic transition on maximal and submaximal aerobic variables to treadmill and bicycle in triathletes. Japanese monitor elite cyclists during a season. Medicine Journal of Physiology 43: 347-360. and Science in Sports and Exercise 25: 1062-1069. Moreira-Da- Costa, M., Russo, A. K., Picarro, I. C., Basset, F. A. and Boulay, M. R. (2000) Specificity of Barros Neto, T. L., Silva, A. C. and Tarasantchi, J. treadmill and cycle ergometer tests in triathletes, (1989) Oxygen consumption and ventilation during runners and cyclists. European Journal of Applied constant-load exercise in runners and cyclists. Physiology and Occupational Physiology 81: 214- Journal of Sports Medicine and 221. 29: 36-44. Boulay, M. R. (1995) Physiological monitoring of elite Mujika, I. and Padilla, S. (2000a) Detraining: loss of cyclists. Sports Medicine 20: 1-11. training-induced physiological and performance Boulay, M. R., Simoneau, J. A., Lortie, G. and Bouchard, adaptations. Part I: short term insufficient training C. (1997) Monitoring high-intensity endurance stimulus. Sports Medicine 30: 79-87. exercise with heart rate and thresholds. Medicine Mujika, I. and Padilla, S. (2000b) Detraining: loss of and Science in Sports and Exercise 29: 125-132. training-induced physiological and performance Bunc, V. and Heller, J. (1989) Energy cost of running in adaptations. Part II: Long term insufficient training similarly trained men and women. European stimulus. Sports Medicine 30: 145-154. Journal of Applied Physiology and Occupational Pechar, G. S., McArdle, W. D., Katch, F. I., Magel, J. R. Physiology 59: 178-183. and De Luca, J. (1974) Specificity of Coast, J. R. and Welch, H. G. (1985) Linear increase in cardiorespiratory adaptation to bicycle and optimal pedal rate increased power output in cycle treadmill training run. Journal of Applied ergometry. European Journal of Applied Physiology 36: 753-756. Physiology and Occupational Physiology 53: 339- Perez, H. R. (1981) The effects of competitive road- 342. racing on the body composition, pulmonary Fernhall, B. and Kohrt, W. (1990) The effect of training function, and cardiovascular system of sport specificity on maximal and submaximal cyclists. Journal of Sports Medicine and Physical physiological responses to treadmill and cycle Fitness 21: 165-172. ergometry. Journal of Sports Medicine and Pichot, V., Roche, F., Gaspoz, J. M., Enjolras, F., Physical Fitness 30: 268-275. Antoniadis, A., Minini, P., Costes, F., Busso, T.,

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Lacour, J. R. and Barthelemy, J. C. (2000) Relation AUTHORS BIOGRAPHY: between heart rate variability and training load in Fabien A. BASSET middle-distance runners. Medicine and Science in Employment: Sports and Exercise 32:1729-1736. Research Assistant, Kinesiology Ricci, J. and Leger, L. A. (1983) VO2max of cyclists from Division Department of Social and treadmill, bicycle ergometer and velodrome tests. Preventive Medicine, Faculty of European Journal of Applied Physiology and Medicine, Laval University, CAN Occupational Physiology 50: 283-289. Degree: Schneider, D. A., Lacroix, K. A., Atkinson, G. R., PhD Troped, P. J. and Pollack, J. (1990) Ventilatory Research interest: threshold and maximal oxygen uptake during , Sports cycling and running in triathletes. Medicine and Performance Science in Sports and Exercise 22: 257-264. E-mail: Schneider, D. A. and Pollack, P. (1991) Ventilatory [email protected] threshold and maximal oxygen uptake during Marcel R. BOULAY cycling and running in female triathletes. Employment: International Journal of Sports Medicine 12: 379- Professor, Kinesiology Division, 383. Department of Social and Preventive Swain, D. P. and Leutholtz, B. C. (1997) Heart rate Medicine, Faculty of Medicine, reserve is equivalent to %VO2 reserve, not to Laval University, CAN %VO2. Medicine and Science in Sports and Degrees: Exercise 29: 410-414. Ph.D, MBA Swain, D. P., Leutholtz, B. C., King, M. E., Haas, L. A. Research interest: and Branch, J. D. (1998) Relationship between % Exercise Physiology, Sports heart rate reserve and %VO2 reserve in treadmill Performance, Genetic, Anatomy exercise. Medicine and Science in Sports and Exercise 30: 318-321. * Fabien A. Basset, Ph.D. Van Handel, P. J., Baldwin, C., Puhl, J., Katz, A., Division de Kinésiologie, Département de Médecine Dantine, S. and Bradley, P. W. (1988) Sociale et Préventive, Faculté de Médecine, Université Measurement and interpretation of physiological Laval, Ste-Foy (Québec), Canada G1K 7P4 parameters associated with cycling performance. In: Medical and scientific aspects of cycling. Ed: Burke E. R. and Newsom M. Human Kinetics Books, Champaign, IL, 47-72. Verstappen, F. T., Huppertz, R. M. and Snoeckx, L. H. (1982) Effect of training specificity on maximal treadmill and bicycle ergometer exercise. International Journal of Sports Medicine 3: 43-46. Viru, A. and Viru, M. (1993) The specific nature of training on muscle: a review. Sports Medicine Training and Rehabilitation 4: 79-98. Weltman, A., Snead, D., Seip, R., Schurrer, R., Weltman, J., Ruttand, R. and Rogol, A. (1990) Percentages of maximal heart rate, heart rate reserve and VO2max for determining intensity in male runners. International Journal of Sports Medicine 11: 218-222. Zhou, S., Robson, S. J. and Davie, A. J. (1997) Correlations between short-course triathlon performance and physiological variables determined in laboratory cycle and treadmill tests. Journal of Sports Medicine and Physical Fitness 37: 122-130.